We participate in many Microsoft go-live programs, beta programs and we have launched new features and source code in beta to get feedback as well.
We put this Labs site together to consolidate these different offers and betas.

OPEN BETA PROGRAMS

[CLOSED] FREE .NET 4.5.1 Preview Hosting Sandbox
The developer community is invited to experience next-generation web development using .NET 4.5.1 on Windows Server 2012 R2.
The program ends: October 31, 2013

[CLOSED] FREE .NET 4.5.1 Preview Hosting Sandbox
The developer community is invited to experience next-generation web development using WebMatrix v3.
The program ends: August 1, 2013